Electric switch



Aug. 19, 1930.

5. M. KENER SON ELECTRIC SWITCH Filed Sept. 13, 1928 2 Sheets-Sheet 1 ea/*0 5M aha/62 .5 g;

Aug. 19, 1930.. s. M. KENEQRSON ELECTRIC SWITCH Filed Sept. 13, 1928 2Sheets-Sheet 2 5 ini? v i i.

at? W10 3 all? I Alibi flz /iw Patented Aug. 19, 1930 I UNITED STATESPATENT OFFICE STANLEY M. KENERSON, F SPRINGFIELD, MASSACHUSETTS,ASSIGNOR TO STANDARD ELECTRIC TIME COMPANY, OF SPRINGFIELD,MASSACHUSETTS, A

CONNECTICUT CORPORATION OF ELECTRIC SWITCH Application filed September13, 1928. Serial No. 805,808.

The subject matter of this invention is intended primarily for use bypatients in hospitals to close a plurality of signal circuits (leadingfor example to a light over the door of the patients room, a light overthe nurses desk or in the diet kitchen, a buzzer at the nurses desk, anannunicator at a suitable location, a light in the patients room to indcate that the signals function properly, etc.) but in various aspectsthe invention may be used in connection with one or moreclrcuits for anypurpose whatsoever. Objects of the invention are to provide a switchwhich is readily portable, which is neat and attractive in appearance,which is simple and econom1 cal in construction, which is durable andefficient in use, which can be readily assembled and disassembled, andwhich is generallysuperior to switches of this general type asheretofore constructed.

For the purpose of illustrating the genus of the invention, concreteembodiments are illustrated in the accompanying drawings, in which 2.

Fig. 1 is a side elevation of the preferred embodiment Fig. 2v is asection on line 2-2 of Fig. 1;

Fig. 3 is an end view (looking from the bot tom of Figs. 1 and 2) withone part of the casing removed;

Fig. 4 is a side elevation of the plunger of the switch, parts beingshown in cross section;

Fig. 5 is an end view (looking from the top of Figs. 1 and 2) with thecasing and the insulating disk removed; 7

Fig. 6 is an axial section of a modification, the casing being removed;v I

Fig. 7 is a section on line 7,-7 of Fig. 6;

Fig. 8 is a front view of pull-chain modification;

Figs. 9 and 10 are sections on lines 9-9 and 10-1O respectively of Fig.8; and

Fig. 11 is a View similar to Fig. 2 showing the switch of Figs. 9 and10-applied to a'portable casing for push-button operation insteadof'pulhchain control.

The particular embodiment of the invention shown in Figs. 1 to 5comprises a casing formed in tn 3, parts 1 and 2, threaded together at3, a base 4 of insulating material mounted in casing 1 by a peripheralflange clamped between the two casing parts with peripheral portions onopposite sides of the flange which telescope into the parts 1 and 2, apair of contacts 5 and6 mounted on the rear (the top in Fig.2) of thebase 4, as shown in Figs. 2- and 5, four L-shaped contact springs 7, 8,9 and 10 mounted at 7, 8', 9 and 10' on the front of the support 4, asshown in Figs. 2 and 3, and a plunger 11 for actuating the springcontacts. As shown in Figs. 2 and '3, the insulating support 4 has acylindrical extension on its rear face, portions of this extension beingcut away to accommodate'the springs 5 and 6, thus dividing the extensioninto two parts 12 and 13 (Fig. 5). Resting on the face of this extensionis an insulation disk 14 to hold the wires bunched in the end of thecasing 1 away from the contacts 5 and 6, the wires extending to thevarious contacts either through perforations in the disk 14 or throughnotches in its periphery.

The plunger 7 comprises a circular piece of insulation 15 having aconducting ring 16 mounted in a circumferential groove near its forwardend and having axial bores to receive the spring 17 and the metallicportions of the plunger comprising a head 18 projecting from the casing,a reduced portion 19 extendin through the spring, a larger portion 20proJeCting from the rear end of the insulation sleeve 15, and anotherreduced portion 21 projecting to the rear, a finger piece 22 beingmounted on the reduced portion 21 and projecting laterally toward orthrough 'a, slot 23 in the casing 2. The parts 18, 19 and'20' slidefreely but snugly in the insulation sleeve 15, the spring 17 normallyholding the portions in the retracted position shown in Figs.

2 and 4. The portions 18, '19, 20 and 21 may be formed integrally withone another, or any two or more of these portions may 'befformedseparately and attached together and to the other portions in anysuitable manner, as by threading or a pressed fit. The finger 22 may bewelded or brazed in position, or attached by a pressed fit, or theportion 21 may be threaded into the portion 20 with a shoulder holdingthe finger 22 against the end of the portion 20. The finger 22 mayproject through the casing, as shown in Fig. 2, so as to be actuated bythe finger outside of the casing, or it may terminate short of theopening 22 so that an instrument must be inserted through the opening inorder to actuate the finger.

The operation of the embodiment shown in Figs. 1 to 5, inclusive, is asfollows: The parts normally stand in the position shown in Fig. 2, withall of the circuits open, the spring fingers 7, 8, 9 and 10 engaging thetapered portion 21 of the plunger to hold the plunger in the retractedposition. When the plunger 11 is forced inwardly by pressure on theprotruding portion 18, each of the spring contacts 7, 8, 9 and 10contact with the ring 16 of the plunger, thereby closing the respectivecircuits through the ring 16. The plunger is then held in advancedposition either by the friction of the spring contacts 7, 8, 9 and 10,or preferably by the contacts hooking over the ring 16 at their inclinedportions (Fig. 2). As shown in Fig. 2, the insulation base 1 may beprovided on its forward face with a cylindrical extension 26 to engagethe insulation sleeve 15 of the plunger and thereby limit the extent towhich the insulation sleeve is advanced toward the rear, the cylindricalextension 26 being provided with a slot 27 to accommodate the finger 22.\Vhen the sleeve 15 reaches its innermost position, further pressure onthe finger piece 18 causes the parts 18, 19. 20, 21 and 22 to advancestill further, sliding in the cylinder 15,whereby the projection 21engages the contact 6 and presses this contact against the contact 5. Bymaking the spring 17 stiff enough to predominate over the springs 7, 8,9 and 10, the circuits through the contacts 7, 8, 9 and 10 may be closedwithout closing the contacts 5 and 6; whereas, if the spring 17 isweaker than the springs 7, 8, 9 and 10, then the contacts 5 and 6 arenecessarily closed when the circuit through 7, 8, 9 and 10 are initiallyclosed. Thns, when using the switch 56 for operating a buzzer in ahospital system of the character above described, the tension of thesprings may be so proportioned that the buzzer circuit is closed whenthe light circuits through 7, 8, 9 and 10 are initially closed, or sothat the buzzer circuit may be closed at a later time by furtherpressure on the finger piece 18, as for example after getting noresponse to the light signals. As shown in Fig. 5 the contact 6 is heldby the same rivet 10 which holds spring contact 10, thereby connectingthe two contacts 6 and 10 together. Vhen thus mounted the two contacts 6and 10 are connected to a common battery lead, the other contacts 5, 7,8 and 9 being connected to individual buzzer and light circuitsrespectively which ultimately connectwith the other side of the obattery. Thus when ring 16 contacts with spring fingers 7, 8, 9 and 10the light circuits connected to 8, 9 and 10 are closed through ring 16to the common return connected to 6 and 10; and when contact 5 ispressed against contact 6 the buzzer circuit connected to 5 is closedthrough the common return connected to 6 and 10.

The modification shown in Figs. 6 and 7 is in general similar to theembodiment shown in Figs. 1 to 5, inclusive, corresponding parts beingcorrespondingly designated. However, in this modification the plunger isprovided with a cross bar 27 fast on a sleeve which in turn is fast tothe sleeve 15, the ends of the bar 7 having semi-cylindrical notchesfitting over guide pins 26 mounted in the insulation support 4. Portion21 of the plunger has an integral flange 28 to act as a stop and aninsulation tip 29 to engage spring 6. In this form of the inventionfinger 22 is formed integrally with the bar 27.

The form of the invention shown in Figs. 8 to 11 inclusive is similar,to the preceding forms, particularly that shown in Figs. 6 and 7, and ingeneral comprises a circular base 31 of insulating material, a plunger32 having an outer sleeve 33 of insulating material, and a plunger 34reciprocating longitudinally in the sleeve 33 and normally held inextended position as shown in Fig. 9 by a spring, as illustrated in Fig.6, the construction of the plunger 32 being the same as that shown inFigs. 6 and 7 except that the part 34 has an integral flange 35 and anannular groove 36. The L-shaped spring fingers 37 which contact with themetallic ring 39 when the plunger is moved inwardly to the positionshown in Fig. 10 are mounted in radial recesses or grooves in theforward side of the base 31 in the same manner as illustrated in Fig. 7,that is, by terminal connectors in the form of rivets extending throughthe base. contact 39 corresponding to 5 of Fig. 6 is in the form of abar (Fig. 9') mounted at each end by eyelets 40 on the segmental raisedportions of the base between the aforesaid grooves in which the springfingers 37 are mounted; and the contact 41, corresponding to 6' of Fig.6, is mounted under the base of one of the contact fingers 37 with itsfree end overlapping the bar 39 in spaced relation thereto, the circuitto which the contact 11 and the associated finger 37 are connectedconstituting the common return or the live wire for the other threecontact fingers 37 and the contact bar 39. As in the preceding Fig. 6,the plunger has a tip 42 of insulating material which engages thecontact 41 to press it against the contact 39 when the outer plunger 32is fully advanced and the inner plunger 34 is also fully advanced in theouter plunger Mounted on the inner end of the plunger 32 is a bar .12(corresponding to bar 27 in Fig. 6) which has openings The to receivethe guide pins 43 (Figs. 10 and 11) One end of this bar is extended asshown as shown at 44 in'Figs. 10 and 11 to be engaged by the finger or asuitable instrument to retract the plunger to the normal open-circuitposition shown in Fig. 9.

This form of the invention is adapted to be used either with apull-chain 45, as shown in Figs. 8, 9 and 10, or without a pull-chain,in a manner similar to that described in con nection with Figs. 1 to 7inclusive, as shown "in Fig. 9. When used without a pull-chain,

as shown in Fig. 11, the plunger may be retracted either by pullingoutwardl on the inner plunger 34 or pulling outward y on the projection44 fast to the outer plunger 32, the collar 46 serving to retract theouter plunger 32 when the inner plunger 34 is pulled outwardly.

When using that form of the invention shown in Figs. 8 to 11 inclusivein the manner shown in Fig. 11, the insulation base 31 has a peripheralflange mounted between the two casing parts 47 and 48 with thevcircuitconductors connected directly to the contact fingers or the rivetsholding the contactfingers on the base, a central recess 49 beingprovided on the rear face of the base 31 to accommodate the wires asthey pass from the cable 50 to their respective terminals, grooves beingprovided in the rear face of the insulation' base to connect the centralrecess with the marginal recesses containing the heads of the eyeletswhich secure the contact pieces on the base. In order to hold the cable50 tightly to the base 31 a plate 51 and insulation washer 52 areperfectly mounted on the back of the base 31 by means of screws 53 whichthread into the guide ,pins 43 and serve the further purpose of holdingthe guide pins on the front of the base, By making the cable opening inthe disk 51 somewhat smaller than the outer diameter of the cable 50 andthen, before attaching the disk 51 to the base, forcing the cablethrough the opening so'that the covering of rubber or other depressiblematerial is indented by the periphery of the opening with a portionprojecting through the opening, this projecting portion of the cablecoverim is compressed longitudinally and caused tobulge outtransversely, as shown in Fig. 11, when the plate 51 is forced to itsseat by means of the screws 53, the bulging end of the cable coveringbeing clamped tightly between the washer 52 and the bottom of the recess49, as shown in Fig. 11.

' When using this form of the invention in a junction box as shown inFigs. 8,9 and 10 the disk 51 and washer 52 as well as the easing 4748are not used, the base 31 being mounted on the cover plate 54 of thejunction box by means of a ring 55 closely surroundingthe base 31 infront of the flange 56 and mounted onthe cover plate of the junction boxby means of integral straps or legs 57 lever 62 loosely mounted on therear face of the plate 54 by means of a pin 63 so as to rock from thenormal position shown in Fig. 9 to the position shown in Fig. 10 whereinthe forked end 64 of the lever presses,

through the medium of the flange 35, both plungers to their fullyadvanced positions wherein the fingers 37 hook over the ring 38 and theinner plunger 34 is advanced within the outer plunger 32 to engage thecontact 41 and press it against the contact 39. As in the precedingembodiments contacts 39 and '41 may engage simultaneously with theengagement of the four contacts 37 with ring 38 or subsequently thereto,depending upon the strength of the coil spring between thetwo plungers33 and 34 relatively to the strength of springs 37; also the innerplunger 34 is automatically retracted in the outer plunger 33 when thechainis released, the outer plunger being retracted only by pullingoutwardly on the protruding portion 36 of the inner plunger 34.

When using the pull-chain embodiment of the invention with signalcircuits for hospitals the advance of the outer plunger until the ring38 interconnects the four spring fingers 37 may be used to light threesignal lamps at suitable locations and the further advance of the innerplunger 34 within the outer plunger 32 may be used to close a buzzercircuit through the contacts 39 and 41 as in the preceding embodiments.

While the outer and inner plungers are hereinafter referred to as themain and auxiliary plungers respectively, it will be underv stood thatthe outer plunger might be used as an auxiliary plunger and the innerplunger as a main plunger; also that the switches ma be arranged to opencircuit or otherwise mo ify circuit connections, instead of closingcircuit, when the plungers are advanced inwardly or to the rear; thatmeans other than a coil spring may be used automatically to retract theone plunger relativelyto the other; that means other than the fingers7-10 or 7 10 or 37 may be employed for holding the main or outer plungerin advanced position; that the'spring means typified by the coil springmay be interposed between the plunger or actuators so that the plungerswill move together in response to force applied to the main instead ofthe auxiliary plunger in which case the auxiliary switch would of coursebe positioned to function before the main switch on switches; that thetwo plungers or actuators may be slidably or movably interconnectedotherwise than by telescoping together; that the plungers reciprocatealong a line intersecting the insulation base, the two plungers andcircular base preferably being coaxial; and that many othermodifications may be made within the scope of the appended claims.

I claim:

1. An electrical switch comprising a plurality of plungers reciprocablerelatively to each other, a switch cooperating with one plunger when theplunger is actuated, a switch cooperating with the other plunger when itis reciprocated relatively to the first plunger, and means forindefinitely holding one plunger in operative position while the otherplunger is in inoperative position.

2. An electrical switch comprising main and auxiliary actuators movabletogether and relatively to each other, a spring normally holding theauxiliary actuator retracted relatively to the main actuator, a switchresponsive to actuation of the main actuator, another switch responsiveto advance of the auxiliary actuator relatively to the main actuatoragainst the action of said spring and means for actuating one plungerindependently of the other.

3. An electrical switch comprising inner and outer plungers telescopedtogether, a plurality of contacts cooperating with the outer plunger tomodify a circuit when the outer plunger is actuated, a plurality ofother contacts cooperating with the inner plunger to modify a circuitwhen the inner plunger is moved relatively to the outer plunger, andmanual means for moving one plunger to circuit-modifying positionwithout moving the other plunger.

4. An electrical switch comprising a plurality of plungers reciprocablerelatively to' each other, a switch cooperating with one plunger whenthe plunger is actuated, a switch cooperating with the other plungerwhen it is reciprocated relatively to the first plunger, means forautomatically retracting the second plunger relatively to the firstplunger without retracting the first plunger.

5. An electrical switch comprising main and auxiliary actuators movabletogether and relatively to each other, a spring normally holding theauxiliary actuator retracted relatively to the main actuator, a switchresponsive to actuation of the main actuator, another switch responsiveto advance of the auxiliary actuator relatively to the main actuatoragainst the action of said spring, and

means for holding the main actuator in advance position while permittingthe auxiliary actuator to retract relatively to the main actuator.

6. An electrical switch comprising main and auxiliary actuators movabletogether in response to a force applied to the auxiliary actuator andthe auxiliary actuator having further movement relatively to the mainactuator in response to such force, and a spring interposed between thetwo actuators for normally holding the auxiliary actuator retractedrelatively to the main actuator.

7. An electrical switch comprising inner and outer plungers slidablytelcscoped together, a spring normally holding one plunger retractedrelatively to the other plunger, a switch responsive to advance of thelatter plunger, and another switch responsive to further advance of thefirst plunger against the action of said spring.

8. An electrical switch comprising inner and outer plungers slidablytelescoped together, a spring normally holding one plunger retractedrelatively to the other plunger, a switch responsive to advance of thelatter plunger, another switch responsive to further advance of thefirst plunger against the action of said spring, a face plate supportingsaid plungers therebehind to reciprocate forwardly and rearwardly, apull extending through an opening in the plate, and meansinterconnecting said pull and plungers behind the plate to reciprocatethe plunger-s rearwardly when the pull is pulled forwardly.

9. An electrical switch comprising a face plate, a plunger mountedbehind said plate to reciprocate forwardly and rearwardly relatively tosaid plate, a pull extending through an opening in the plate, and meansinterconnecting said pull and plunger behind the plate to reciprocatethe plunger rearwardly when the pull is pulled forwardly.

10. An electrical switch comprising a face plate, a plunger mountedbehind said plate to reciprocate forwardly and rearwardly relatively tosaid plate, a pull extending through an opening in the plate, and alever interconnecting said pull and plunger behind the plate toreciprocate the plunger rearwardly when the pull is pulled forwardly.

11. An electrical switch comprising a face plate, a plunger mountedbehind said plate to reciprocate forwardly and rearwardly relatively tosaid plate, a pull extending through an opening in the plate, and meansinterconnectingsaid pull and plunger behind the plate to reciprocate theplunger rearwardly when the pull is pulled forwardly, said plungerhaving a portion projecting through an opening in the plate forreciprocating the plunger forwardly.

12. An electrical switch comprising a face plate, a plunger mountedbehind the plate to reciprocate forwardly and rearwardly relatively tothe plate, a pull extending through an opening inthe plate toreciprocate the plunger, an insulation base having a peripheral flange,and a base support having parts 1;

clamping said flange therebetween, one of said parts having legsstraddling said plunger and attached to the back of said face plate.

13. An electrical switch comprising a base of insulation material havinga peripheral flange, a base support having parts clamping said flangetherebetween, switch contacts mounted on the base, and a plungerextending through an opening in said support for actuating saidcontacts.

14. An electrical switch comprising a base of insulation material havinga peripheral flange, a base support having parts clamping said flangethcrebetween, switch contacts mounted on the base and a plungerextending through an opening in said support for actuating saidcontacts, said flange being intermediate the ends of the base so thatthe peripheral portions of the base on opposite sides of the flangesextend into said parts respectively.

15. An electrical switch comprising a base of insulation material havinga peripheral flange, a base support having parts clamping said flangetherebetween, L-shaped switch contacts mounted on the front of the base,a plunger engaging said contacts, and terminal connections extendingthrough the base for attachment to circuit conductors.

' 16. An electrical switch comprising an insulation base, a plungerreciprocating toward and from the base, L-shaped switch contacts mountedon the front of the base for engagement with the plunger, and terminalconnectors extending through the base for attachment to circuitconductors at the rear of the ase.

17. An electrical switch comprising an insulation base, a plungerreciprocating along a line intersecting the plane of the base, the basehaving recesses extending radially of said line, circuit connectionsmounted in said recesses, and plunger engaging switch contacts mountedon the base in circuit with said connectors respectively.

18. An electrical switch comprising an 'insulation base, a plungerreciprocating along .a line intersecting the plane of the base, the basehaving superposed radial recesses on its front and rear surfacesrespectively, switch contacts mounted in the front recesses forengagement with said plunger, and circuit connectors mounted in the rearrecesses in electrical communication with said contacts respectively.

Si ned by me at Boston, Massachusetts, this fth day of Se tember, 1928.

STANL Y M. KENERSON.

